1. Field of the Invention
The present invention relates to an image-signal processing device, an image-signal processing method, and an image display apparatus, in particular, which are capable of achieving wide gradation expression when enlarged display is performed.
2. Description of the Related Art
Hitherto, an increase in the resolution of image display apparatuses has been achieved. For example, the resolution of image display apparatuses is increased from a high definition (HD) size of 1920×1080 pixels to a 4K2K size of 3840×2160 pixels. On the other hand, image signals are mainly generated for the HD size. When the image display apparatuses having a resolution that has been increased are used, scalers or the like are generally used as described in Japanese Unexamined Patent Application Publication No. 2005-354187.
Furthermore, an increase in the number of bits in a case of generation of image signals or image processing has been achieved. In a case of generation of image signals, for example, generation of ten-bit or twelve-bit image signals has been performed. Additionally, in a case of image processing, for example, conversion of a bit depth is performed so that eight-bit image signals are converted into ten-bit image signals. Using the image signals that are obtained by conversion, brightness correction, color correction, correction of gradation characteristics, and so forth are performed.